1. Field of the Invention
The present invention relates generally to a communication system, and more particularly, to a method for transmitting and receiving a session history in a communication system.
2. Description of the Related Art
Due to the improvement in performance of recent terminals and the expansion of bandwidths for wireless communications, advanced communication infrastructures have been built, enabling services, which were previously available only in a wired environment, to also be executable in a wireless environment. To meet the diverse needs of users, these services should be providable in all Internet Protocol (IP)-based wired/wireless networks. Accordingly, to meet these demands, Open Mobile Alliance (OMA), which is a global mobile standardization body, has attempted to integrate (or converge) Mobile services and IP-based services by proceeding with a Converged IP Messaging (CPM) session.
Protocols used to provide these integrated or converged services may include a Session Initiation Protocol (SIP), a Message Session Relay Protocol (MSRP), and a Real time Transfer Protocol (RTP).
Among these protocols, SIP, which is defined in the Internet Engineering Task Force (IETF) Request for Comment (RFC) 3261 standard document, is an application-level signaling protocol for establishing, modifying, and terminating a session for multimedia communication such as video and audio communication. More specifically, the SIP sends and receives messages in a request/response manner with protocols existing on User Datagram Protocol (UDP)/Transmission Control Protocol (TCP)/IP layers. The SIP-based request messages include INVITE (invitation to join the session), ACK (acknowledgement of invitation request), BYE (session termination), REGISTER (register location information of user clients in a database of a register server), CANCEL (cancel pending request), and OPTIONS (request for server information), as defined in RFC 3261. The SIP-based response messages include 1xx (information response), 2xx (affirmative response), 3xx (redirection response), 4xx (client error), 5xx (server error), and 6xx (global error), as status codes.
The MSRP, which is defined in the IETF RFC 4975 standard document, is used to transmit text data in a session. Specifically, the MSRP attempts to address shortcomings that transmitting text data using the existing SIP-based MESSAGE messages does not consider associations between the messages, and that the SIP-based MESSAGE messages include a SEND (message sending) message and a REPORT (message sending confirmation) message.
FIG. 1 illustrates a conventional CPM system.
Referring to FIG. 1, the CPM system includes a CPM client 100, e.g., a mobile terminal, and a network apparatus including a CPM Conversation Server (CS) 110, a CPM Controlling Function (CF) unit 120, an application control function unit 130, an interworking selection function unit 140, an interworking function unit 150, a message and media storage client 160, and a Message and Media storage Server (M&MS) 170. The M&MS 170 may be provided as a separate component, or may be included in the CS 110.
The CPM client 100, i.e., a service requestor, creates a session to another CPM client through the CS 110, and receives services from the another CPM client. The M&MS 170 stores data exchanged over a session created between CPM clients and determines whether to store CMP session data, based on a user preference and/or a service provider policy.
The CF 120 creates and manages a session between the CPM client 100 and the CS 110. In other words, if a group session is created, the CF 120 creates a session between the CPM client 100, the CS 110, and the CF 120 in its user domain. After the session is created, the CF 120 sends messages received from the CPM client 100, or a subscriber of the group session, to other subscribers of the group session. The domains may be separated by the service provider.
A set of all kinds of data exchanged between CPM clients, from the start of a session until the present, will be referred to herein as a “session history”. The session history is managed by a CPM Conversation History Function (CHF, not shown) in the CS 110, and may be stored in the M&MS 170 and the CPM CHF in the CS 110.
Currently, a session history of a one-to-one session is managed in the CPM CHF in the CS 110, and is temporarily stored in the M&MS 170 or the CPM CHF in the CS 110. The session history of a one-to-one session may be individually managed by CSs in different domains, and may be optionally stored, depending on a user preference and/or a service provider policy.
A method of tracking history information of a group session is disclosed in U.S. Patent Publication No. 2007/0100908, filed by Neeraj Jain, and entitled “Method and Apparatus for Tracking History Information of a Group Session” (hereinafter referred to as “Jain”). However, group selection should precede the tracking in Jain. In addition, creating a group session, and transmitting and receiving a session history are not disclosed in detail in Jain.